Screening ultrasound as an adjunct to mammography in women with mammographically dense breasts

Abstract

There is increasing interest in the potential benefits and harms of screening ultrasound to supplement mammographic screening of women with dense breast tissue. We review the current evidence regarding adjunctive screening breast ultrasound (US) and provide a summary for clinicians who counsel patients with dense breasts. We conducted a comprehensive literature review of published clinical trials and observational cohort studies assessing the efficacy of screening handheld US (HHUS) and automated breast US (ABUS) to supplement mammography among women with dense breasts. From a total of 189 peer-reviewed publications on the performance of screening US, 12 studies were relevant to our analysis. The reporting of breast cancer risk factors varied across studies; however, the study populations tended to be at greater than average risk for developing breast cancer. There is consistent evidence that adjunctive screening US detects more invasive cancers compared to mammography alone, but there is currently no evidence of associated long-term breast cancer mortality reduction. The studies also collectively found that US was associated with an additional 11.7–106.6 biopsies/1,000 examinations (Median 52.2), and detected an additional 0.3–7.7 cancers/1,000 examinations (Median 4.2). The associated number of unnecessary breast biopsies resulting from adjunct US screening exceeds that observed with screening mammography alone by approximately 5-fold. Adjunctive screening with ultrasound should also be considered in the context of screening mammography. It is important for clinicians to be aware that improvements in cancer detection in mammographically dense breasts have been achieved with the transition from film to digital mammography, reducing a limitation of film mammography. Clinicians should discuss breast density as one of several important breast cancer risk factors, consider the potential harms of adjunctive screening, and arrive at a shared decision consistent with each woman’s preferences and values.

Photoacoustic Imaging in Oncology: Translational Preclinical and Early Clinical Experience

“…When mammography is combined with other screening techniques such as US or tomosynthesis, the cancer detection rates increase from 6.1/1000 using mammography alone (4.4% false-positive rate) to 8/1000 using mammography plus tomosynthesis (5.3% false-positive rate) and 11.8/1000 using mammography plus US (10.4% false-positive rate) in high-risk women (51,52). When US is used as an adjunctive screening technique to mammography, positive predictive values of as low as 5.6% were reported (53). These rates indicate that many women are called back for unnecessary biopsies, which leads to increased health care costs and psychological stress for women.…”

An Investigation into the Consistency in Mammographic Density Identification by Radiologists: Effect of Radiologist Expertise and Mammographic Appearance

“…Increased MD also potentially lowers the sensitivity of mammography by obscuring small masses [4,5]. Accurate and reliable assessment of MD has crucial clinical significance, as women with high MD are often referred for additional magnetic resonance imaging (MRI) or ultrasound examinations in order to increase the likelihood of early breast cancer detection [6,7]. Up to now, 19 states of the USA have signed legislation requiring that women are told of their MD status when they attend mammographic breast examinations [8].…”

3D Supine Automated Ultrasound (SAUS, ABUS, ABVS) for Supplemental Screening Women with Dense Breasts

“…In addition, opponents of 3D supine automated breast ultrasound may argue that previous ABUS and ABVS studies showed an average 10 percent lower detection rate, higher rate of false positives and higher recall rates compared to physician-performed whole breast HHUS (1,2,5). More shadowing artefacts created by angulated Cooper ligaments and fibrous structure, especially at the periphery of the breast are causing false positive cases and may need supplementary characterization to differentiate a pseudo lesion from a real lesion by use of HHUS, Doppler and elastographic techniques.…”

“…Women with heterogeneous and extremely dense breast tissue show a 3-5 times higher relative risk than women with fatty breasts as referenced in meta-analysis, but only a 2 times higher relative risk than women with scattered fibroglandular tissue (18). Recommendations to overcome masking in women with dense breasts focus on MRI, ultrasound and, more recently digital tomosynthesis (2,17).…”

“…More shadowing artefacts created by angulated Cooper ligaments and fibrous structure, especially at the periphery of the breast are causing false positive cases and may need supplementary characterization to differentiate a pseudo lesion from a real lesion by use of HHUS, Doppler and elastographic techniques. Furthermore, final US-guided biopsy is based on HHUS-guidance, so as a result, "onestop-shop" ABUS is only effective for negative cases (2,15).…”